Background: The lung of patients with cystic fibrosis (CF) is particularly sensitive to Pseudomonas aeruginosa. This bacterium plays an important role in the poor outcome of CF patients. During the disease progress, first acquisition of P. aeruginosa is the key-step in the management of CF patients. Quantitative PCR (qPCR) offers an opportunity to detect earlier the first acquisition of P. aeruginosa by CF patients. Given the lack of a validated protocol, our goal was to find an optimal molecular protocol for detection of P. aeruginosa in CF patients. Methods: We compared two formerly described qPCR formats in early detection of P. aeruginosa in CF sputum samples: a qPCR targeting oprL gene, and a multiplex PCR targeting gyrB and ecfX genes. Results: Tested in vitro on a large panel of P. aeruginosa isolates and others gram-negative bacilli, oprL qPCR exhibited a better sensitivity (threshold of 10 CFU/mL versus 730 CFU/mL), whereas the gyrB/ecfX qPCR exhibited a better specificity (90% versus 73%). These results were validated ex vivo on 46 CF sputum samples positive for P. aeruginosa in culture. Ex vivo assays revealed that qPCR detected 100 times more bacterial cells than culture-based method did. Conclusion: Based on these results, we proposed a reference molecular protocol combining the two qPCRs, which offers a sensitivity of 100% with a threshold of 10 CFU/mL and a specificity of 100%. This combined qPCR-based protocol can be adapted and used for other future prospective studies.

Human endogenous retrovirus group E (HERV-E) elements are stably integrated into the human genome, transmitted vertically in a Mendelian manner, and are endowed with transcriptional activity as alternative promoters or enhancers. Such effects are under the control of the proviral long terminal repeats (LTR) that are organized into three HERV-E phylogenetic subgroups, namely LTR2, LTR2B, and LTR2C. Moreover, HERV-E expression is tissue-specific, and silenced by epigenetic constraints that may be disrupted in cancer, autoimmunity, and human placentation. Interest in HERV-E with regard to these conditions has been stimulated further by concerns regarding the capacity of HERV-E elements to modify the expression of neighboring genes and/or to produce retroviral proteins, including immunosuppressive env peptides, which in turn may induce (auto)-antibody (Ab) production. Finally, better understanding of HERV-E elements may have clinical applications for prevention, diagnosis, prognosis, and therapy.

Background: Increasing resistance to antibiotics ofPseudomonas aeruginosaleads to therapeutic deadlock and alternative therapies are needed. We aimed to evaluate the effects ofLactobacillusclinical isolates in vivo,through intranasal administration on a murine model ofPseudomonas aeruginosapneumonia.Results: We screened in vitro 50 pulmonary clinical isolates ofLactobacillusfor their ability to decrease the synthesis of two QS dependent-virulence factors (elastase and pyocyanin) produced byPseudomonas aeruginosastrain PAO1.Two blends of threeLactobacillusisolates were then tested in vivo: one with highly effective anti-PAO1 virulence factors properties (blend named L.rff forL. rhamnosus, twoL. fermentumstrains), and the second with no properties (blend named L.psb, forL. paracasei, L. salivariusandL. brevis). Each blend was administered intranasally to mice 18 h prior to PAO1 pulmonary infection. Animal survival, bacterial loads, cytological analysis, and cytokines secretion in the lungs were evaluated at 6 or 24 h post infection with PAO1.Intranasal priming with both lactobacilli blends significantly improved 7-day mice survival from 12% for the control PAO1 group to 71 and 100% for the two groups receiving L.rff and L.psb respectively. No mortality was observed for both control groups receiving either L.rff or L.psb. Additionally, the PAO1 lung clearance was significantly enhanced at 24 h. A 2-log and 4-log reduction was observed in the L.rff + PAO1 and L.psb + PAO1 groups respectively, compared to the control PAO1 group. Significant reductions in neutrophil recruitment and proinflammatory cytokine and chemokine secretion were observed after lactobacilli administration compared to saline solution, whereas IL-10 production was increased.Conclusions: These results demonstrate that intranasal priming with lactobacilli acts as a prophylaxis, and avoids fatal complications caused byPseudomonas aeruginosapneumonia in mice. These results were independent of in vitro anti-Pseudomonas aeruginosaactivity on QS-dependent virulence factors. Further experiments are required to identify the immune mechanism before initiating clinical trials.

Pseudomonas aeruginosa plays a major role in cystic fibrosis (CF) progression. Therefore, it is important to understand the initial steps of P. aeruginosa infection. The structure and dynamics of CF respiratory tract microbial communities during the early stages of P. aeruginosa colonization were characterized by pyrosequencing and cloning-sequencing. The respiratory microbiota showed high diversity, related to the young age of the CF cohort (mean age 10 years). Wide inter- and intra-individual variations were revealed. A common core microbiota of 5 phyla and 13 predominant genera was found, the majority of which were obligate anaerobes. A few genera were significantly more prevalent in patients never infected by P. aeruginosa. Persistence of an anaerobic core microbiota regardless of P. aeruginosa status suggests a major role of certain anaerobes in the pathophysiology of lung infections in CF. Some genera may be potential biomarkers of pulmonary infection state.

A fatal case of enterovirus 71 infection with pulmonary edema and rhombencephalitis occurred in Brest, France, in April 2007. The virus was identified as subgenogroup C2. This highly neurotropic enterovirus merits specific surveillance outside the Asia-Pacific region.

Point-of-care syndromic PCR (POC SPCR) assays are useful tools for the rapid detection of the most common causative agents of community-acquired infections responsible for meningitis and encephalitis infections. We evaluated the performance characteristics of the new QIAstat-Dx^® Meningitis/Encephalitis panel (QS) compared to the laboratory reference methods and the POC SPCR Biofire^® FilmArray^® Meningitis Encephalitis Panel (FA). Viral (Enterovirus, Parechovirus, HSV-1, HSV-2, HHV-6, VZV) and bacterial (E. coli K1, H. influenzae, L. monocytogenes, encapsulated N. meningitidis, M. pneumoniae, S. agalactiae, S. pneumoniae, S. pyogenes) pathogens were suspended at low concentrations and tested with the POC SPCR systems. The reproducibility, analytical specificity, carryover contamination, interferences and clinical samples were evaluated. All samples tested positive with both QS and FA except for those containing the lowest concentrations of Enterovirus-D68-B3, Echovirus-30 and S. agalactiae which were only detected by FA. In terms of analytical specificity, we observed 3 false positive results out of 48 QS tests versus 1 out of 37 FA tests. For the other studied criteria, both QS and FA performed as expected. Our results suggest that the performance characteristics of QS are close to those of FA. A prospective multicenter study would be useful to complete the performances evaluation of QS.